Observation of nonthermal energy distributions during the impulsive phase of solar flares

Journal Article · Sat Aug 01 04:00:00 EDT 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165477· OSTI ID:5930494

Seely, J F; Feldman, U; Doschek, G A

The Fe XXV resonance line and dielectronic satellite intensities have been measured as functions of time for several flares recorded by the Naval Research Laboratory crystal spectrometer (SOLFLEX) flown on the US Air Force P78-I spacecraft. The intensity ratios of the Fe XXV resonance line, the Fe XXIV n = 2 satellite line j, and the Fe XXIV n = 3 satellite line d13 indicate that nonthermal electron energy distributions occur during the impulsive phase of the flares. For the electron energies at which the j and d13 satellites are formed (4.7 and 5.8 keV, respectively), the electron energy distributions during the impulsive phase are observed to have a bump or to be nearly flat. For all of the flares that were studied, hard X-ray bursts occurred near the time of the nonthermal distributions observed in the SOLFLEX data. 25 references.

• Research Organization: E. O. Hulburt Center for Space Research, Washington, DC
• OSTI ID: 5930494
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 319; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY SPECTRA
FERMIONS
FLUORESCENCE
HARD X RADIATION
IONIZING RADIATIONS
IRON
LEPTONS
LUMINESCENCE
METALS
RADIATIONS
RESONANCE FLUORESCENCE
SATELLITES
SOLAR ACTIVITY
SOLAR FLARES
SOLAR X-RAY BURSTS
SPECTRA
TIME DEPENDENCE
TRANSITION ELEMENTS
X RADIATION